package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    // 开始时间戳
    private static final long BEGIN_TIMESTAMP=1640995200L;
    private static final int COUNT_BITS=32;

    // 生成全局唯一id
    public long nextId(String keyPrefix){
        // 拼接上业务前缀
        LocalDateTime now=LocalDateTime.now();
        long nowSecond=now.toEpochSecond(ZoneOffset.UTC);
        long timestamp=nowSecond-BEGIN_TIMESTAMP;
        // 生成序列号
        // 获取当前日期，精确到天
        String date=now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        // 自增长
        long count=stringRedisTemplate.opsForValue().increment("icr"+keyPrefix+":"+date);
        // 拼接并返回（使用或运算）
        return timestamp<< COUNT_BITS | count;
    }

//    public static void main(String[] args) {
//        // 记录开始的时间戳
//        LocalDateTime time=LocalDateTime.of(2022,1,1,0,0,0);
//        long second=time.toEpochSecond(ZoneOffset.UTC);
//        System.out.println("second = " + second);
//    }
}
